//
//  ZHMainTabBar.swift
//  ZHweibo
//
//  Created by Henry on 3/21/16.
//  Copyright © 2016 Henry. All rights reserved.
//

import UIKit

// TabBarItem个数
let tabBarItemCount=5

class ZHMainTabBar: UITabBar {

    override func layoutSubviews() {
        super.layoutSubviews()
        
        // 计算 item的宽度
        let width=frame.width / CGFloat(tabBarItemCount)
        // 计算最左边的这个frame,后面使用CGRectOffset
        let originFrame=CGRect(x: 0, y: 0, width: width, height: frame.height)
        var index = 0
        for view in subviews{
            let cls = NSClassFromString("UITabBarButton")
            if view.isKindOfClass(cls!){
                // rect: 原始的frame
                // dx: x方向的偏移量
                // dy: y方向的偏移量
                view.frame=CGRectOffset(originFrame, CGFloat(index) * width, 0)
                index += index == 1 ? 2 : 1
                
            }
            
            
        }
        
        // 设置加号按钮frame
        composeButton.frame=CGRectMake(2*width, 0, width, frame.height)
        
        
    }
    //mark: -懒加载-
    //加号按钮
    private lazy var composeButton: UIButton = {
        let button = UIButton()
        // 设置
        button.setBackgroundImage(UIImage(named: "tabbar_compose_button"), forState: UIControlState.Normal)
        button.setBackgroundImage(UIImage(named: "tabbar_compose_button_highlighted"), forState: UIControlState.Highlighted)
        
        button.setImage(UIImage(named: "tabbar_compose_icon_add"), forState: UIControlState.Normal)
        button.setImage(UIImage(named: "tabbar_compose_icon_add_highlighted"), forState: UIControlState.Highlighted)
        // 添加到tabBar上面
        self.addSubview(button)
        
        
        return button
    }()
 
    
}








